Well jar



' E. KoPPl. x-:TAL

Dec. 94 11952 WELL JAR 3 Sheets-Sheet l Filed Sept. 15, 1946 5y THE/QATToR/vsys E. KOPPI. HAL

Dec, 9, 1952 WELL JAR Filed Sept. l5, 1946 w fw 7/1/ VEN roes.- ER/vEsT KOPP/ go 7 Kop/DL.,

By THE/R ATnuR/veys Dec., 9, M52 E. KoPPL Erm.

WELL JAR 3 Sheets-Sheet 5 WVU/mmf ERNEST KOPPL., LEO 7`. Kop/9L.,

By THE/R Armen/EVS A #Afm/5, MEC/1, 5575/2 HAR/QL? Filed Sept. l5, 1946 |2Jll lll l l l/ l f a w 070g@ Patented Dec. 9, 1952 UNITED, starts TEE QFFICE WELL .mit

Application September 13, 1946, Serial No. 696,880

(Cl. Z55-27) 4 Claims. 1:

This invention relates broadly to the artoi drilling oil wells bya system lwell known as the rotary method. More speciiically, the invention relates to devices known as well jars which are used on the lower ends' of 'strings Yof vdrill pipe for the purpose of 'loosening drillbits and .other pieces of equipment-whichhave become stuck or jammed inthe bottom of wells.

During drilling operations aslthey are conducted in the drilling oif'deep wells,` particularly oil wells, the drill bit, "or'o'ther portion ofthe equipment, occasionally becomes jammed in the drill hole due either to the caving in of the formation being drilled or to some other cause. As a result, the drllbit, or other piece .of equipment, can be neither turned nor withdrawn by ordinary actuation ofthe drill pipetowhich/ it is attached. For the. purpose of rfreeingsuch stuck or jammed equipmentva'riousitypes of jars have been developed, some of whichheretoiore haver beenlfairly satisfactory, "and others not so satisfactory.' Mostof thenilhave been provided with friction-type releases.

It is anobjectofthisninvention to provide for the industry a well jarwhich wllbe positive andefcientin operation, easy to 'operatel relatively simple in constructionand moderate in cost.

Deep well jars of the typetowhiohv the presentl inventionapplies function normallyV by" the transmission of a sudden severe blowto a portion of, thejar which attached'ito` thestuck implement. It is aparticularobjectof this invention to providea Ajarhaving positively operat ing means which servejto release the jary for delivery offthedesired blow, as distinguished from friction means intended to operate uponL development of a predetermined n strain.

A jar of thisftype is actuated by theapplication of a lifting forceiuponV the upper end of drill pipe supported fromthe usual drillvrigl or derrick and suspended in the wellhole, the lower end ofk the drill pipe carrying the jar. When an implement is badly stuck, continuedliiting pro,- duces appreciable stretchy in the drill pipe and thereby generatesa tension or powerfulelastic strain. Inasmuch as a drllpipe 'may be several thousandY fetlong'Y and'is made of steel, the stretch so developed-may amount to several feet. Advantage is taken ofAthis elastic strain to yield the desired sharp blow required for loosening the implementl To eiect release withinrthe jar so that the blow may. be accomplished, latch means or other releasable means is used, this means maintainingrengagement of vthe drill pipe 2 with that portion of the jar. attached tothe stuck rimplement until such', time assuffiGient strain has been developed by the `lifting force applied to the top ofthe pipe. Whenlthisstrain releases thelatch mechanism, they elasticenergy stored in thedrill pipe .by reason of thestretch actsv suddenly tov transmit .a powerfulblow, this blow being conveniently accorri'plsl'iedby` means ofa hammer'member carried by the Idrillppipe andcooperating 'with an anvilmember carried bythe portion ofthe jar vsecured to'. the stuck implement; However, a friction release'fforthe latch means cannot be madet release'uniformly under `any given strain because it hasu been found that such a friction release operates underi one applied forcenat one time and undera substan-lv tially different force at another time.

It is, therefore, an important objectV of this invention to provide a well jar capable of Ybeing always released under a given strain.l It is anotherimportant object of this'l inventionv to vpro-- vide such a jarwhich is capable of being' always released under any selected strain which'the operator may deem desirable. It is a further object to provide such a jar which will operate as indicated under any selected strainwithout the necessity of employing/'any mechanical 'adjust'- ment either within the jar or lat the surfacjof the vwell when itis desired to actuate,thei device under a strain different from that'of the pre'-` ceding operation. W w 'A Another object is to provide, in a jar of the nature indicated, means for simply and automatically resetting the jar `betweenl jarring operations.

Anotherobject is to provide in alwelljar de-` layed action means adapted. to'lcontrol thefoper'-, ation of the neleasing means, andalso to provide for elapse of` appropriate time intervals ,so'gthat the operator may have an opportunity to. establish' the desired strain for any givenjarringy operation. Itis avstill further object top rovide a jar selectively operablev under strains -`ranging'4` from relatively low values to relativehigh values', so thatoperationsmay lbe initiated with low strains, the strains Ibeingsuccessively increased neces; sary, whereby'to lfavor the power 'eduipmentfem ployed for producing. the strains.. 'and thereby prolong. the litev of fthe machinery employed and tliederrick structureirom whichv thefdri'll pipe issuspeededf, l

coordinates preferredembodiment. a Clashpot type oi control means, containing hydraulic iiuid, is usedto `receive initially liressureapplied by way of the lifting and stretching of the drill pipe, a metering pin or the like being used for slowly bleeding trapped hydraulic uid out of the dash-pot. As a plunger moves in the dashpot, tripping means such as levers move into contact with positive actuating means, such as cam faces, whereby the levers or other tripping means are positively moved and the jar is positively released to strike the required blow. Spring means and check valve means serve for quick return of the plunger and resetting oi' the release means.

Other objects and features of the invention will become apparent to those skilled in the art upon reference to the accompanying drawings wherein a useful embodiment of the invention is illustrated.

In the drawings:

Fig. l is a diagrammatic elevational view on a small scale illustrating the jar of the present invention suspended from drill pipe in a deep well below a conventional derrick (not shown);

Figs. 2, 3, and 4 are principally longitudinal sections of the jar on a larger scale and show suceessive portions of the complete jar from top to bottom, the section of Fig. 2 being indicated by the line 2 2 of Fig. 11;

Figs. 5 to '7 are cross-sectional views taken on lines 5 5, 6 6, and 1 1, respectively of Fig. 3;

Figs. 8 and 9 are cross-sectional views taken on the lines 8 8 and 9 9 respectively of Fig. 4;

Fig. l is an enlarged vertical section, as indicated by the line I0 I of Fig. 1l, and showing the mechanism of the lower portion of Fig. 2 and the upper portion of Fig. 3;

Fig. l1 is an enlarged cross section taken on the lines Il II of Figs. 2 and 10; and

Fig. l2 is a still further enlarged fragmentary elevation showing the mounting and structural details of the release levers constituting part of the latch mechanism.

In the form of construction disclosed in the drawings, the principal parts comprise a main mandrel I9 (Fig. 4) to which an inner mandrel i2, constituting a mandrel extension, is secured by threads I2a, these mandrels l0 and I2 being non-rotatably fixed together by a lock pin i3 and telescopically received in a sleeve-like body memer I4. The lower end of the body member I4 has secured thereto a hammer I5 of sleeve-like formation disposed around the main mandrel II) and having its upper end disposed within the bodyy member I4. An upwardly facing annular wall IEa of the hammer I5 is adapted to strike an annular downwardly facing anvil shoulder [E integrally carried by the upper portion of the mandrel I0 within the body member i4 and adjacent the joint between the mandrels EG and I 2.

Within the upper portion of the body member E4 and operatively carried thereby is a latch mechanism I8 (Fig. 3) adapted to cooperate with the upper end of the inner mandrel I2. Attached to the upper extremity of the body member I4 by means of a threaded connection Il) (Fig. 2) is a body joint which, through the medium of a standard box and pin connection 2 I, serves to connect the body member I4 to the lower end of a string of conventional drill pipe 22. The drill pipe 22, as shown in Fig. 1, extends upward to the surface of the well and into a conventional derrick (not shown) equipped with a rotary table 23, block 24, and hoist line adapted for raising and lowering the drill pipe as required. As seen in Fig. 2, the upper end of the inner mandrel I2 is provided with a wash pipe 2S adapted to move through a packing gland 2'I provided in a corre- 4 spending bore of the body joint 2S. For the purpose of attachment of the wash pipe 2S to the inner mandrel I2, the wash pipe 23 is provided with an integral head 28 secured over the end of the inner mandrel by a threaded connection 29 and lock pin or screw 29a.

As seen in Fig. 4, the tubular hammer I5 is slidably and non-rotatably connected with the lower extremity of the main mandrel I9 by means of positioning and driving fingers 3G provided on the lower extremity of the hammer I5 and slidably received in guideways 3I cut in the adjacent portion of the main mandrel Irl. This construction is also illustrated by the cross section of Fig. 9. For convenience of construction, and also for the purpose of providing good seating between the parts, the main mandrel HJ and the hammer I5 are frusto-conically formed as indicated at 32. In order to nx the upper end of the hammer I5 to the lower end of the body member I4, a threaded joint 33 is provided, the upper extremity of the hammer I5 filling an annular space between the body member I4 and the main mandrel Ii) and thereby directing its upwardly facing annular striking wall Ia toward the anvil shoulder I6 to impart the required jarring blows. The anvil shoulder IG is provided by the lower end of an annular anvil 34 integral with the upper portion of the main mandrel I0. The anvil 34 has near its top a plurality of spline-ways 35 which receive between them intertting cooperating, driving and guiding splines 36 integrally provided upon the adjacent inner wall of the body member I4.

As presently to be explained, when the latch mechanism I8 is released to free the body member I4 when placed under proper stretching tension, the annular striking wall I5a imparts a severe blow to the anvil shoulder I6 of the anvil 34 and thereby produces a jar-ring eifect upon any implement attached to the lower end of the main mandrel I0. Such attaching means may be a conventional threaded pin connection IOa adapted to be engaged in a corresponding box of any grapple device such as an overshot S connected in turn to the stuck implement, the latter being generally represented by the drill bit B seen in Fig. 1.

The latch mechanism I8 is disposed in operative position within the body member I4 by being in part mounted upon and about the inner mandrel I2 and in part mounted upon the body member I4 and slidably disposed about the inner mandrel i2 above the threaded connection I2a between the two mandrels. To accomplish these ends the latch mechanism I8 comprises a lower portion 40 (Fig. 3) which slides upon the inner mandrel i2, an upper portion 42 which slides upon the upper portion of the inner mandrel I2 to a lesser extent, and release levers 44 which operatively connect the lower and upper portions 4() and 42.

rlhe levers 44 are fulcrumed upon a nangelike annular bearing head 45 carried upon the upper end of a thrust sleeve 46 constituting a part of the lower portion 40 of the latch mechanism and slidably mounted on the lower portion of the inner mandrel I2. Each of the release levers 44, of which four are indicated, are arcuate transversely as seen in Fig. 5. Each lever 44 is grooved as indicated at 4'1 thereby providing (Figs. 3 and 12) an upper bearing shoulder 48 :and a lower retaining shoulder 49, these shoulders 48 and 49 respectively overlying and underlying the flange-like head 45. It will be noted that the portion of the shoulder 48-finwardly1of the groove lll is curved to7 rock upon afY correspondinglyshaped` portion ofy thehead'` 452- rIlhe sleeve @6l-is threaded into the upper portion. of the upper member 50i ofva. two-part.`connecting ring (also constitutinga part .of the" lower :latch portionll) of which. its lowermember .52'.i's.sp1it vertically as indicatedby `a dottedfli'nevrl 531'(Fig..13); to facilitate insertion and removal; The twopart connecting ring 59, 52isempl'oyed1 ii'orthe purpose of bindingv thev sleeve. 4621170; the :body member lll and preventing. longitudinalzmove.- ment ofv the release` levers. 1K4. Landi .the sleeve 4:6 with respect to the body member lliiwh'ennthe inner mandrel l2 slides..within1the,:sleeve;lili; This retention. of the connecting.V ringiilg 52;;is accomplished. through the medium. ofaan'.' internal annular actuatingrib integrallyfcarried bythe inner walll of. the .body memberv L4; An. annular. rubber cushion .56, is, employed; be.- tween. the rib and the connecting.ringmember 52 for the purpose of absorbing-,chatter andare.- sisting wear. The ring members 5d and .5x2-'are secured together by means of 'cap screws. 5l.; As is apparent, the upper. connecting. ring. member 5t isintroduoed fromV above during installation and the two parts of the. lower connectingdring member 52 are introduced'from' .below during installation, the cap screws 5 7 being; also introduced from below and threaded into position with a long. tool. To insure against loosening, of the sleeve FaS in the upper connectingrinamember 50,' a transversely disposed lockingeliititiV may be used if desired. As seen in Fig.A 3, the two ring members 5G. andl 52 are rabbetedl. t0` accommodate the annular rib 55;, and the upper vportion of the upper ring member 50 is offset outwardly to accommodate the lower endofthe sleeve de. Above the upper end of the connecting, ring member 50 and. between the sleeve 46; and the body member lli, there is provided a pressure or bearing ring t whose upper facefis. beveledto provide an annular. resistance sea-t- 52V for the correspondingly beveled lower ends of all of the release levers fifi. The pressure ring S- isnormally urged upward by resettingV springs 63 whose ends are countersunk inthe upper connecting ring member 50 and the pressure ring 6B as shown.

The upper ends of the release levers'lilir cooperate with a hardened compression sleeve B5, which constitutes stop means for-engagement by adjacent ends of the release levers-eiland which in part slidably bears upon the outer wall ofthe inner mandrel l2 but has its lower portion recessed annularly to receive a positive trip ring 5%. The trip ring 66 is non-slidably mounted upon the inner mandrel I2, this being accomplished through the medium of anannular retaining rib El integrally formed upon the outer wall of the inner mandrel I2. The. trpring 66 is split longitudinally for installation uponthe rib 61 and when installed is retained imposition .by the overhanging portion of the compression sleeve 55.. The lower end of the positive trip ring t6 is beveled to provide av cam face E8 adapted to be engaged by correspondingly beveled edges 'ab' on the upper ends of the respective. release levers 44; The upper ends of thelevers eiland the lower annular edge of; the compression sleeve 65 are provided with correspondingly curved and inter-fitting faces 72. These curvatures are approximately as indicated in Fig. l2, and are such that engagement'between them is maintained, regardless of' any pressure applied through the release levers 44; until there has. been. sufli'cient, upwardA movement of the beveled edges. llof: thelevers 44- to. contactthe annular. cam face 68iso thauth-elatter .positively forces the. upper ends oi 'the levers, 44 outward until the heels of the curved faces 12; on the levers 44, pass. the center; line; of; the-curve -of theannular face l2 oir thel lower end, ofthe compression sleeve 65,' the upper ends ofi the levers. 44,. then. automatically,- completing; disengagement frorn the compression sleeveI 65 under Vthe force applied: longitudinally to. thereleaselevers 4,4..

The upper `end of.; the,y harden,ed;c ompression sleeve B zbears .upon the4 corres ponding, lower end cita. .relatively softer spring-receiving barrel 'I5 which .is formed with aninternal annular opening. 'lwhich receives a spring 'l1 (Figs .l3 andlO) referred to herein as. an auxiliar-ry spring; The lower end of the auXiliaryspr-ing Vi bears upon an internal annular seat '18 within the barrel l5, andthe upper end of ,-theauXiliary spring 'Il bea-rs against an annular` auxiliary piston 80 slidably disposed upon an elongated; skirt 8| offa compression piston 82, disposedA around the upper portion of the inner mandrel l2 'adjacent the place where thelatter is `received in the head- 28 of. th-'e wash pipe 26.` The seat 'I8 also receives the lower end of the skirt 8l of the compression piston 82. An annular packing 8,3` seals the piston 82 upon the inner mandrel'` l2, and an anular packing 8i seals the outer wall of the piston S2 upon the inner wallof an outer cylinder 85 having at its upper end a head 86 provided with an elongatedv upper extension 8l. The cylinder head extension 81 isof reduced diameter with respect to the head 86 and extends upward within th-e body joint 2G into engagement withV the lower face of the head 23, of the wash pipe 26 affixed to the upper end of the inner mandrel l2 as above described. The cylinder S5, its head 86, `and the extension 8'1 are continuously urged upward against the wash pipe head 2f8--and away from the compression piston 821 by means of a plurality of power springs 88 disposed between the piston 82 Iand the head 86 and suitably countersunk to maintain their respective positions,

The annular space between the compressi-on piston 82 and the cylinder head 8B and within the cylinder 85' constitutes a high-pressure iiuid chamber S0 for hydraulic liquid, such as oil, used in the system. Below the piston 8 2, an annular low-pressure ilu-idl supply chamber 92 isprovided -between the skirt 8l and the Cylinder 85, and .above the yauxiliary piston 8E.' This pisto n Sil serves as. ar sort of follower and acts both to retain the oil in the system` and automatically-to adjust itself to the oil volume, thus compensating for any toil loss and thereby insuring against entr-ance of drilling mud.

For the purpose of venting as mal-l portionoi the hydraulic liquid upon the initial stroke of the apparatus, whereby to prevent hydraulic lock, the auxiliary piston is. provided with a ball check valve 93 controlling a passage 94 and pressed by a spring 95 held by a vented pluglike retainer 9S. The auxiliary. pist-on 801s provided with packings 9! working upon the adjacent walls of the skirt Sl and the cylinder whereby to retain oil in the supply chamber 92 against pressure imparted thereto.

The'pist-on 82 is a control piston vprovided-w-i'tli means for regulating the time interval determining release of the release levers lli' oi the-latch mechanism I8. The means carried by`v thecontrol piston 82 comprises (Fig. 10) a'hydraulic 7 fluid feed means having a ball check feed valve IOI, -a delayed action mechanism |02 including a bleeder or metering pin |03, and hydraulic fluid return means |04 including a ball check valve |05 (Fig. 2).

The fluid return ball check valve |05 is pressed into position by a spring |06 retained by -a vented retainer plug |01, the ball check valve |05 controlling ilow through a passage |08 between the high pressure chamber 90 and the low pressure chamber 92. The low end of the metering pin |03 of the delayed action mechanism |02 is tapered in conformity with a correspondingly tapered portion of a bore I I0 which communicates through a by-pass III with the high-pressure ychamber 90, whereby liquid under high pressure ln the chamber 90 passes from the bore IIO into the low-pressure chamber 92. The metering pin |03 has yan adjustable threaded connection II2 with the piston 82, and a lock sleeve I|3 (Fig. 10) is threadedly secured upon the metering pin |03 and extends upward into a bore II4 in the reduced extension 81 of the cylinder head 86. The lock sleeve IIS also serves as a guide for the metering pin |03. For the purpose of adjustment, the upper end of the metering pin |03 is provided with a wrench-receiving terminal I03a, and access to this terminal is obtained by means of a sealed removable plug II5, which closes the upper end of the bore II4 during operation, and in addition to providing for adjustment of the metering pin |03 serves as a means for venting air `from the system during filling.

Respecting the duid feed means |00 and the -ball check feed valve I0 I, another bore I I6 similar to the bore II4 is p-rovided in the cylinder head extension 81, this bore receiving a -removable fluid feed plu-g IIB threadedly secured within the upper end of a fluid feed tube whose lower end is normally closed by the ball check valve ISI under the influence of a spring |22 seated Vagainst a shoulder |23 provided in a stepped passage |24 leading into the low-pressure fluid supply chamber 52. The upper end of the fluid feed plug IIB is provided with a tool-receiving terminal Iia whereby to install and remove the plug. The bore IIS is normally closed by a removable sealed plug |25 which, together with the plug II5, is pressed against the underside of the wash pipe head 28. As shown, the cylinder head extension 61 is annularly packed at |28 upon the outer wall of the inner mandrel I2.

The construction just described, namely that comprising the piston 82, its skirt 0 I the auxiliary piston 80, the cylinder head 86, and associated parts, constitutes a dash-pot whereby the passage of hydraulic uid under high pressure from the high-pressure fluid chamber 90 to the supply chamber 92 is regulated by the metering pin |03, fluid being restored past the ball check valve |05 upon each return movement of the piston 82.

Assembly In order that the hammer I5 may be assembled upon the lower end of the main mandrel I0 between the anvil 34 and the enlarged exposed lower portion of the main mandrel I0, the hammer I5 is initially split longitudinally to form two-semicylindrical parts. Assembling of the hammer I5 upon the mandrel I0 includes welding the two members of the hammer I5 together while positioned upon the mandrel I0 below the anvil 34. After welding, the hammer I5 is machined and its upper end threaded for the purpose of completing the threaded joint 33 with the lower end of the body member I4.

However, before threading the hammer member I5 into position in the body member I4, with incidental positioning of the main mandrel I0, the latch mechanism I8 and associated members are first installed in the top of the body member I4, and this is accomplished before the body joint 20 is threaded into place. To accomplish such positioning of the latch mechanism I8, the upper ring member 50 and the pressure ring 60, together with the resetting springs 63, are placed upon the thrust sleeve and the lock pin 50 is inserted to insure retention of the desired relationship. The parts thus assembled are then introduced part way into the upper end of the body member, and the release levers 44 are mounted upon the annular head 45 of the thrust sleeve 46, whereupon these assembled portions are then further introduced into the upper end of the body member I4. This operation may be carried out with the mentioned parts assembled on the lower end of the inner mandrel I2, or the inner mandrel I2 may be later inserted into the thrust sleeve 46. At such time, the split positively acting trip ring 66 will be positioned about the retaining rib 61, and the compression sleeve 65, the spring receiving barrel 15, the auxiliary spring 'I1 and the compression piston S2, with associated parts, installed. At an appropriate time, the outer cylinder 85, with its head 86 and extension 81, is installed upon the upper portion of the inner mandrel I2. The inner mandrel I2, carrying the parts thus assembled thereon, is introduced into the body member I4 to the operative position shown in Figs. 2, 3, and 4.

Thereupon, the two portions of the lower ring member 52 are inserted from the open lower end of the body member I4 and the cap screws 51 threaded into place with a suitable tool. The annular rubber cushion 56 will have been placed upon the annular actuating rib 55 at any appropriate earlier` assembling stage. The cap screws 51 having been secured, the main mandrel I0 is next introduced into the lower end of the body member I4, the guiding splines 36 being received in the splineways 35, and the upper end of the hammer I5 being threaded into place to secure the parts as shown. The inner mandrel I2, carrying the parts retained thereon by the rib 61, is next threaded into position in the upper portion of the main mandrel I0 to make the threaded joint I2a. The final operation resides in placing the wash pipe 26 upon the upper end of the inner mandrel I2 through the medium of the threaded connection 29 and the lock pin 20a, and then passing the body joint 20 over the wash pipe 26 and threading it into operative position by making the threaded connection I0.

The lock pin I3, if used to secure the outer and inner mandrels I0 and I2 against unthreading at the joint I 2a, will be installed at any desired stage through a hole which may be filled with a plug |35 or may be left open for passage of drilling fluid to equalize pressures within and without the body member I4. To permit passage of such fluid, and in View of the fact that the ring members and 52 and the annular rubber cushion 56 tends to form a sealed joint, uid passages |36 are provided through the assembled ring members 50 and 52 and the thrust sleeve 46, as indicated in Fig. '1. In this way the annular chamber housing, the release levers 44 and other parts of the latch mechanism I8 is in communication with the chamber within the body 9 member H enclosing the upper end of the main mandrel Ill.l yThe latter has a'ii-t within the body member-lll' and the Ahammer I5 sufficiently loose to= pass equalizingfluidwhether'or not the plug |35 is used,`and also to permitfreemovement of the hammer l'tothe shoulder IS of the anvil 315.

Filling hydraulic device A step preliminary to operation, which step may be performed during initial assembly or Yat a later time, is the fillingwith the v'hydraulic liquid of the high and low pressure chambers ee and 92 respectively. 'For this purpose,the body joint 20 and the wash pipe 2B vw'illhave been removed. The sealed plugs |I and '|25 Vand' the feed plug ||8 are removed. Under these conditions, the power springs '88 separate the compression piston 82 vfrom the' cylinder head SS to the limit of the extension of the springs 83;'or about as illustrated i'n Fig. 2.

A liquid injecting gun is then attached to the feed tube |2-by any suitable fitting, and oil'is forced past the ball-check 'valve IB I', and through the'passage |241, into the low pressure chamber 92 whence, after filling the latter,` the oil 'is moved past the ball'check valve |85 'into' the high pressure chamber.

Air in the'sy'stem vents through the tapered bore wand the passage |8 from' the lower pressure chamber 92 and 'through' the bores M `and H from the high pressure lchamber 95. rIhe metering pin E33 is adjustedtoV predetermine the bleeding rate of the liquid through the by-pass The 'auxiliary piston-8 is forced down by the applied liquid pressure 'against the auxiliary spring 'il as desired, the'power of the spring |96 on the ball checkvalve Illi being suflicient to permitsuch complete filling andthe safety valve spring 95 being strong enough to avoid leakage past vthe'ball check valve 9 3 inthe auxiliary piston 86; All air having' been vented, lthe `sealed plug H5 is placed; the filling gun "removed, the feedpplug H8 restored, and the sealed plug |25 placed. Y- Y Operation nection is made in a conventional manner with i;

the ystuck bit B or other stuck' t'ool. The parts are now in approximately thepositions shown in the drawings.

Strain is then applied to the drill pipe 22 through the hoist line Zto` any selected mini- 1 mum value which it is thought-is apt to loosen the stuck tool. Such a value is determined by a'weight indicator or similar gauge asl conventionally used at the ground surface in well drilling operations. This strain,thefvalue of which mightbe; for example, 50Q0 pounds, produces a corresponding stretchkr or elongation in thel drill pipe, an'dtl'iereby stores elastic energyin the drill pipe.

Under these conditions, the release levers iid bear against the lower edge of the compression sleeve or stop means 55, being there retained by reason of their curved interltting faces l2. At the same time, the influence of the resetting springs 63 tends to maintain the release levers d!! in the indicated latched position shown by reason of the function of the outwardly inclined annular resistance seat 52 of the bearing ring 5S.

The application of strain and the production of stretch in the drill pipe causes oil or other Liu hydraulic liquid in the Vpressure chamber 9E! to bleed-through the by-pass -I and the tapered bore 'HAB past the metering pinA |03. into ythe low,

pressure chamber 92.v Such compression lupon the-body of .oil inthe highlpressure. chamber 9G is necessarily produced by reason of the force transmitter fromthe...outer body memberV IQ through the actuating rib .55,Lth'e upper .ring member 50, the .thrust sleeve; `the release levers M by way ofv their bearing'ishoulders', to-the compression sleeve 55 and thence through the base of the barrel 'I5 .tothe skirt 8| and the compression piston 82. A

.The metering` pin |03 is so set as to retard the bleeding -operation'fora substantial length of timein order that opportunity maybe .provided reestablish. any required strainY in the drill pipe with a inarginal vtime factor.' before the upper ends of Vthe Vrelea'setlevers .4,4 will. have been dislodged bythe cam action of the positive triprinig." l'

.It will bei noted that the power in the springs E38 (which Vmay totalanyappropriate value, such as-lOOOv pounds) is additive to the hydraulic pressure produced' byV the elastic energy stored'in the'drilllpipe'. It is'also to be noted that; the amount of elastic energystored'in the drill pipe has no influence onithe'tripping'of'the release levers lid, the'curve'd intertting faces-72 of the engaging'portions of the'levers 441| and the compression sleeve being "ofsuchshape as to prevent 'suclractionf On the other-hand; the lrelease levers M are trippedby 'the' positivedisplacement Aactionl between the beveled edges -i ofthe' leversk 4 andthe beveledcam face 158 of the tripring 66,"the 'position ofthe latter-bein'g fixed on the inner vmandrel |2 by the rib 6l. Due to thestrain'imposed uponfthe drill *pipe through the hoist line-25 -and' the consequent pressure applied to the hydraulic fluid rinthe high'pressure chamber 99, thebleeding of the iiuid past the metering 'pin' |03 permits the-compression piston" 82,-' andv hence :the 'release levers Ii'an'd interposed membersr-65 y'and 4'|5,to rise slowly until ther tripringl '66 has-'performed its function of dislodging the upper-endsofthe release'levers fromthe lowereedge of the-compression' sleeve |55. This-condition having developed, theelastic energy-stored in the-drill pipe causes the release Alevers M toiride'upalongsideth'ev compression' sleeve- 65,'-andthe stored elastic `energy""also\causesthefannular striking wall' |5a of'thehammer'i "to produce a--severe blow upon. the annular` anvil shoulder` le ofl the anvil 3% v'carried =by the main mandrel Iii. This blow is transmitted through the fmainmandrel G to the stuck tool B rfith which itis-cr-nnected.-

Should the-blow applied tothe anvil -Sil be -insufficienttoE release thestuck tool, a more powerhierv is next'apfplied-.f This is accom leasing the strain imposed-by the-h1 that the outer body-niem-feridlff the iai mechanisn settles dow-n into'th'ez-initial` position`shof\vn in the drawings, this action resulting in fa relatively upward movement of the main mandrel Iii and its anvil 31% and also of the inner mandrel l2 and its trip ring St, together with the outer cylinder 35 and its head 85. Duringr these movements, the action of the springs 88 to restore the compression piston 32 and the cylinder head 86 to their relative initial positions causes hydraulic uid to return from the low pressure chamber 92 to the high pressure chamber 9@ past the return ball check valve |05 and against the influence of the spring |96. At the same time, the upper ends of the release levers 44 move sufciently below the lower edge of the compression sleeve 65 for the resetting springs 63 and the beveled resistance seat 62 of the pressure ring 60 to restore the release levers 44 to the initial position illustrated.

The operator at the surface of the well now applies through the hoist line 25 a greater strain than previously applied, for example, 7000 pounds. While the hydraulic fluid bleeds from the high pressure chamber 90 past the metering pin |03 somewhat faster under this increased pressure than under the previously employed lower pressure, nevertheless, the setting of the pin |03 is such that, regardless of the strain applied through the hoist line 25, the bleeding action will be slow enough to permit ready attainment of whatever strain is desired before the release levers 44 are tripped by the trip ring 6B. It is merely necessary to wait longer for the tripping action to take place when smaller strains v are applied than when greater strains are applied,

From the foregoing, it will be apparent that the operator of this jarring mechanism is enabled to start his procedures with the application of a minimum strain through the hoist line 25. If the original estimate of the strain required is insulcient, a successive operation takes place with a somewhat increased strain. 1n this manner successive small increases may be employed, either is apparent that undue wear and hardship upon the Various pieces of equipment is avoided, thereby saving the surface apparatus to the maximum extent.

Thus, by employment of the jar of the present mechanism, any selected tonnage blow may be applied as required, such selection, as indicated by a strain indicator, being made certain because of the fact that the tripping of the release levers is positively made and is accomplished only after elapse of suflicient time to provide for the application of the selected tonnage. Also, once the metering pin |03 has been set for a given range of operations up to a maximum tonnage to be applied, no mechanical adjustment is required, either at the surface or elsewhere, as the operations proceed. A further important feature is the automatic resetting of the parts by the springs 83, the springs 63 and the ring 60 upon release of the strain through the hoist line 25 between successive jarring operation.

Since improvements will become apparent to those skilled in this art, it is intended to cover all such variations of the generic invention as fall within the scope of the claims.

We claim as our invention:

1. Well jar mechanism comprising in combination: two elongated members, one within the other and movable longitudinally relative to each other, one being adapted for connection with a drill pipe through which longitudinal strain may be applied; anvil means carried by one of said members; hammer means carried by the other of said members to strike a blow upon said anvil means by reason of longitudinal strain produced through said drill pipe; bearing means carried by one of said members; yielding stop means carried by th other of said members; elongated releasable latch means between and cooperating with said members, opposite ends of said latch means normally engaging said bearing means on said one of said members and said stop means on said other of said members to prevent relative movement between said hammer and anvil means until release of said latch means; latch-releasing means carried by the inner one of said members in position adjacent the respective end of said latch means and in the path of the latter to engage and release the latter; and delayed action means connected with said yieldable stop means to effect actuation of the latter into position for release of said latch means by said latch-releasing means, said delayed action means carrying said stop means and including a hydraulic cylinder carried by the inner one of said members and contaniing hydraulic iluid, a piston working in said cylinder and carried by the inner one of said members, and bleeder means in one of said cylinder and piston for slowly relieving hydraulic pressure created in said cylinder by said strain.

2. A combination as in claim 1 wherein said bleeder means comprises a metering pin disposed in a bleeder bore in said piston.

3. A combination as in claim 1 wherein said stop means is carried by said piston moving on said inner member, and said latching-releasing means is relatively xed on said inner member.

4. A combination as in claim 1 including spring loading means carried in said cylinder and piston as auxiliary means to assist said hydraulic pressure in resisting application of said strain to move said piston.

ERNEST KOPPL. LEO T. KOPPL.

REFERENCES CITED The following references are of record in the iile of this patent:

UNITED STATES PATENTS Number Name Date 1,530,803 Anderson Mar. 24, 1925 1,849,879 McCullough Mar. 15, 1932 1,977,110 Burns et al Oct. 16, 1934 2,055,683 Edwards Sept. 29, 1936 2,122,751 Phipps July 5, 1938 2,126,241 Black Aug. 9, 1938 2,166,299 Kennedy et al July 18, 1939 2,172,480 Osmun Sept. 12, 1939 2,309,872 Shaffer et al Feb. 2, 1943 

